MUSEUM OF COMPARATIVE ZOOLOGY. Gl 



P. (Mangilia) pelagia n. s. 



Shell slender, thin, white, smooth but not polished, with eight whorls ; 



nucleus small, three apical whorls inflated, white, perfectly smooth ; remain- 

 der indistinctly keeled midway between the sutures by a ridge, over which, the 

 lines of growth passing obliquely, the shell is as it were pinched up at regular 

 intervals into oblique projections, ten to fourteen on each whorl, fewer propor- 

 tionally on the larger whorls ; shell otherwise not sculptured ; suture distinct, 

 not appressed; canal and aperture long and narrow, notch well marked, but 

 not forming a distinct band. Lou. of shell, 10.75 ; of last whorl, 7.25 ; of 

 aperture, 5.25. Lat. of shell, (about) 3.5 mm. 



Station 44, 539 fms. 



This is distinctly abyssal in its facies. The specimen, though somewhat 

 imperfect, presents such distinct and recognizable characters as to authorize 

 its description. Other specimens will doubtless be found in the Agassiz-Bart- 

 lett series as yet untouched. Its generic place is, like that of the Last-mentioned 

 species, a little uncertain as between Bela and Mangilia. 



P. (Drillia) polytorta n. s. 



Shell large, slender, solid, with about thirteen whorls, of a dull ashen color 

 and unpolished surface ; nucleus ? ; succeeding whorls transversely sculp- 

 tured by twelve or thirteen rounded, shouldered ribs, beginning and I 

 just before the notch-band, crossing the whorls a little obliquely or even in a 

 directly transverse direction, widest at the beginning, becoming narrower and 

 less prominent anteriorly, on the last whorl fading out or indistinct on the 

 anterior half, and less numerous or partially obliterated over the latter pari of 

 this whorl in fully developed adults; the lines of growth are more or less 

 distinct, but not uniform, while the ribs on one whorl bear no uniform relation 

 in position to those on the next or preceding whorls ; longitudinally each whorl 

 is appressed in a thickened hand against the suture, next in front of which 

 band is the (except on the last half-whorl) narrow unsculptured hand indicating 

 the path of the notch ; this on the last half-whorl widens out considerably if 

 the specimen in hand be typical, though in this ease it may be an individual 

 characteristic ; before the notch-band, and even encroaching a Little on it. and 

 extending over the surface of the whorls, are six or seven (on the last whorl 

 seventeen) slightly raised rounded revolving lines, with slightly wider shallow 

 interspaces, which are about equally prominent over the transverse ribs and 

 between them ; other sculpture none ; aperture rather short and narrow. 

 Blightly more than one third the whole length of the shell ; outer Lip probably 

 thickened ; a considerable amount of smooth callus on the body whorl and 

 pillar; notch rather narrow, of variable depth at differenl stages; canal short, 

 rather open, nearly Straighl ; last whorl less than half the length of the shell. 

 Lon. 33.5. Max. diam. 8.0. bat. of aperture, 5.5 mm. Defl. about 27°. 



Off Cape San Antonio, 413 tins. 



